Method and apparatus for handling measurement in wireless communication system

ABSTRACT

A method and an apparatus for handling measurement operations in a wireless communication system are provided. The method includes a UE receiving a first measurement configuration in system information from a first serving cell. The first measurement configuration indicates at least one first cell applicable for being measured by the UE in a first Radio Resource Control (RRC) state which is an RRC idle state or an RRC inactive state. The method further includes the UE performing, in the first RRC state, a first measurement operation based on the first measurement configuration to generate a first measurement result of the at least one first cell and retaining the first measurement result when the UE transitions from the first RRC state to a second RRC state.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present disclosure claims the benefit of and priority to provisionalU.S. Patent Application Ser. No. 62/862,228 (“the '228 provisional”),filed on Jun. 17, 2019, entitled “MEASUREMENT REPORT THROUGH 2-STEPRANDOM ACCESS PROCEDURE.” The contents of the '228 provisional are fullyincorporated herein by reference for all purposes.

FIELD

The present disclosure generally relates to wireless communications, andmore particularly, to methods and apparatuses for handling measurementin a wireless communication system.

BACKGROUND

With the tremendous growth in the number of connected devices and therapid increase in user/network traffic volume, various efforts have beenmade to improve different aspects of wireless communication for the nextgeneration wireless communication system, such as the fifth generation(5G) New Radio (NR), by improving data rate, latency, reliability andmobility.

The 5G NR system is designed to provide flexibility and configurabilityto optimize the network services and types, accommodating various usecases such as enhanced Mobile Broadband (eMBB), massive Machine-TypeCommunication (mMTC), and Ultra-Reliable and Low-Latency Communication(URLLC).

However, as the demand for radio access continues to increase, thereexists a need for further improvements in the art.

SUMMARY

The present disclosure is directed to methods and apparatuses forhandling measurement in a wireless communication system.

According to an aspect of the present disclosure, a method performed bya User Equipment (UE) is provided. The method includes a UE receiving afirst measurement configuration in system information from a firstserving cell. The first measurement configuration indicates at least onefirst cell applicable for being measured by the UE in a first RadioResource Control (RRC) state which is an RRC idle state or an RRCinactive state. The method further includes the UE performing, in thefirst RRC state, a first measurement operation based on the firstmeasurement configuration to generate a first measurement result of theat least one first cell and retaining the first measurement result whenthe UE transitions from the first RRC state to a second RRC state (e.g.,the UE may retain the first measurement result during and after the RRCstate transition from the first RRC state to the second RRC state).

According to another aspect of the present disclosure, a UE is provided.The UE includes a memory and at least one processor coupled to thememory. The at least one processor is configured to receive a firstmeasurement configuration in system information from a first servingcell. The first measurement configuration indicates at least one firstcell applicable for being measured by the UE in a first RRC state whichis an RRC idle state or an RRC inactive state. The at least oneprocessor is further configured to perform, in the first RRC state, afirst measurement operation based on the first measurement configurationto generate a first measurement result of the at least one first celland retain the first measurement result during (and after) the RRC statetransition (e.g., when the UE transitions from the first RRC state to asecond RRC state). In some implementations, the target componentcarriers of first measurement configuration may include any combinationsof frequency component carriers on licensed bands and un-licensed bands.In addition, the measurement configuration may also include the targetcells, which may operate on licensed bands and un-licensed bands, as theobjectives for UE measurements.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. Variousfeatures are not drawn to scale. Dimensions of various features may bearbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a diagram illustrating a UE configured with several ComponentCarrier (CC)s with multiple active Bandwidth Parts (BWPs) in each CC, inaccordance with an implementation of the present disclosure.

FIG. 2 illustrates a signaling flow of carrier management through a2-step Random Access (RA) procedure, in accordance with animplementation of the present disclosure.

FIG. 3A illustrates a signaling flow of an early measurement procedure,in accordance with an implementation of the present disclosure.

FIG. 3B illustrates a signaling flow of an early measurement procedurethrough a 4-step random access procedure, in accordance with animplementation of the present disclosure.

FIG. 4 illustrates a signaling flow of a measurement negotiationprocedure, in accordance with an implementation of the presentdisclosure.

FIGS. 5 and 6 are diagrams illustrating different formats of MAC CEs, inaccordance with implementations of the present disclosure.

FIG. 7 is a diagram illustrating a procedure of msgA transmissionaccording to the beam operation, in accordance with an implementation ofthe present disclosure.

FIG. 8 is a diagram illustrating a cross-cell reporting procedureperformed by a UE, in accordance with an implementation of the presentdisclosure.

FIG. 9 illustrates a signaling flow between a UE and a Primary Cell(PCell), in accordance with an implementation of the present disclosure.

FIG. 10 illustrates a flowchart of a procedure performed by a UE, inaccordance with an implementation of the present disclosure.

FIG. 11 illustrates a signaling flow among a UE and multiple servingcells, in accordance with an implementation of the present disclosure.

FIG. 12 illustrates a signaling flow among a UE and multiple servingcells, in accordance with an implementation of the present disclosure.

FIG. 13 illustrates a block diagram of a node for wirelesscommunication, in accordance with various aspects of the presentdisclosure.

DETAILED DESCRIPTION

The following description contains specific information pertaining toexemplary implementations in the present disclosure. The drawings in thepresent disclosure and their accompanying detailed description aredirected to merely exemplary implementations. However, the presentdisclosure is not limited to merely these exemplary implementations.Other variations and implementations of the present disclosure willoccur to those skilled in the art. Unless noted otherwise, like orcorresponding elements among the figures may be indicated by like orcorresponding reference numerals. Moreover, the drawings andillustrations in the present disclosure are generally not to scale, andare not intended to correspond to actual relative dimensions.

The following description contains specific information pertaining toexample implementations in the present disclosure. The drawings in thepresent disclosure and their accompanying detailed description aredirected to merely example implementations. However, the presentdisclosure is not limited to merely these example implementations. Othervariations and implementations of the present disclosure will occur tothose skilled in the art. Unless noted otherwise, like or correspondingelements among the figures may be indicated by like or correspondingreference numerals. Moreover, the drawings and illustrations in thepresent disclosure are generally not to scale, and are not intended tocorrespond to actual relative dimensions.

For the purpose of consistency and ease of understanding, like featuresare identified (although, in some examples, not shown) by numerals inthe example figures. However, the features in different implementationsmay differ in other respects, and thus shall not be narrowly confined towhat is shown in the figures.

References to “one implementation,” “an implementation,” “exampleimplementation,” “various implementations,” “some implementations,”“implementations of the present disclosure,” etc., may indicate that theimplementation(s) of the present disclosure so described may include aparticular feature, structure, or characteristic, but not every possibleimplementation of the present disclosure necessarily includes theparticular feature, structure, or characteristic. Further, repeated useof the phrase “in one implementation,” “in an example implementation,”or “an implementation,” do not necessarily refer to the sameimplementation, although they may. Moreover, any use of phrases like“implementations” in connection with “the present disclosure” are nevermeant to characterize that all implementations of the present disclosuremust include the particular feature, structure, or characteristic, andshould instead be understood to mean “at least some implementations ofthe present disclosure” includes the stated particular feature,structure, or characteristic. The term “coupled” is defined asconnected, whether directly or indirectly through interveningcomponents, and is not necessarily limited to physical connections. Theterm “comprising,” when utilized, means “including, but not necessarilylimited to”; it specifically indicates open-ended inclusion ormembership in the so-described combination, group, series and theequivalent.

Additionally, for the purposes of explanation and non-limitation,specific details, such as functional entities, techniques, protocols,standard, and the like are set forth for providing an understanding ofthe described technology. In other examples, detailed description ofwell-known methods, technologies, system, architectures, and the likeare omitted so as not to obscure the description with unnecessarydetails.

Persons skilled in the art will immediately recognize that any networkfunction(s) or algorithm(s) described in the present disclosure may beimplemented by hardware, software or a combination of software andhardware. Described functions may correspond to modules that may besoftware, hardware, firmware, or any combination thereof. The softwareimplementation may comprise computer executable instructions stored oncomputer readable medium such as memory or other type of storagedevices. For example, one or more microprocessors or general-purposecomputers with communication processing capability may be programmedwith corresponding executable instructions and carry out the describednetwork function(s) or algorithm(s). The microprocessors orgeneral-purpose computers may be formed of Applications SpecificIntegrated Circuitry (ASIC), programmable logic arrays, and/or using oneor more Digital Signal Processor (DSPs). Although some of the exampleimplementations described in this specification are oriented to softwareinstalled and executing on computer hardware, nevertheless, alternativeexample implementations implemented as firmware or as hardware orcombination of hardware and software are well within the scope of thepresent disclosure.

The computer readable medium includes but is not limited to RandomAccess Memory (RAM), Read-Only Memory (ROM), Erasable ProgrammableRead-Only Memory (EPROM), Electrically Erasable Programmable Read-OnlyMemory (EEPROM), flash memory, Compact Disc Read-Only Memory (CD-ROM),magnetic cassettes, magnetic tape, magnetic disk storage, or any otherequivalent medium capable of storing computer-readable instructions.

A radio communication network architecture (e.g., a Long Term Evolution(LTE) system, an LTE-Advanced (LTE-A) system, or an LTE-Advanced Prosystem) typically includes at least one Base Station (BS), at least oneUE, and one or more optional network elements that provide connectiontowards a network. The UE communicates with the network (e.g., a CoreNetwork (CN), an Evolved Packet Core (EPC) network, an Evolved UniversalTerrestrial Radio Access network (E-UTRAN), a Next-Generation Core(NGC), or an Internet), through a Radio Access Network (RAN) establishedby the BS.

It should be noted that, in the present disclosure, a UE may include,but is not limited to, a mobile station, a mobile terminal or device, auser communication radio terminal. For example, a UE may be a portableradio equipment, which includes, but is not limited to, a mobile phone,a tablet, a wearable device, a sensor, or a Personal Digital Assistant(PDA) with wireless communication capability. The UE is configured toreceive and transmit signals over an air interface to one or more cellsin a RAN.

A BS may include, but not limited to, a Node B (NB) as in the UniversalMobile Telecommunication System (UMTS), an evolved Node B (eNB) as inthe LTE-A, a Radio Network Controller (RNC) as in the UMTS, a BaseStation Controller (BSC) as in the Global System for Mobilecommunications (GSM)/GSM EDGE Radio Access Network (GERAN), an ng-eNB asin an E-UTRA (Evolved Universal Terrestrial Radio Access) BS inconnection with the 5GC, a next generation Node B (gNB) as in the 5GRadio Access Network (5G-RAN), and any other apparatus capable ofcontrolling radio communication and managing radio resources within acell. The BS may serve one or more UEs through a radio interface to thenetwork.

A BS may be configured to provide communication services according to atleast one of the following Radio Access Technologies (RATs): WorldwideInteroperability for Microwave Access (WiMAX), GSM (often referred to as2G), GERAN, General Packet Radio Service (GPRS), UMTS (often referred toas 3G) based on basic Wideband-Code Division Multiple Access (W-CDMA),High-Speed Packet Access (HSPA), LTE, LTE-A, eLTE, NR (often referred toas 5G), and LTE-A Pro. However, the scope of the present disclosureshould not be limited to the above mentioned protocols.

The BS may be operable to provide radio coverage to a specificgeographical area using a plurality of cells being included the RAN. TheBS may support the operations of the cells. Each cell is operable toprovide services to at least one UE within its radio coverage. Morespecifically, each cell (often referred to as a serving cell) mayprovide services to serve one or more UEs within its radio coverage,(e.g., each cell schedules the Downlink (DL) and optionally Uplink (UL)resources to at least one UE within its radio coverage for DL andoptionally UL packet transmissions). The BS may communicate with one ormore UEs in the radio communication system through the plurality ofcells. A cell may allocate sidelink (SL) resources for supportingproximity service (ProSe) or Vehicle-to-Everything (V2X) services or NRsidelink services. Each cell may have overlapped coverage areas withother cells. In MR-DC cases, the PCell of an MCG or the PrimarySecondary cell (PSCell) of an SCG may be called as a Special Cell(SpCell). PCell may refer to the SpCell of an MCG. A Primary SecondaryCell (PSCell) may refer to the SpCell of an SCG. MCG means a group ofserving cells associated with the Master Node (MN) or the Master BaseStation, comprising of the SpCell and optionally one or more SecondaryCells (SCells). SCG means a group of serving cells associated with theSecondary Node (SN) or the Secondary Base Station, comprising of theSpCell and optionally one or more SCells.

As discussed above, the frame structure for NR is to support flexibleconfigurations for accommodating various next generation (e.g., 5G)communication requirements, such as eMBB, mMTC and URLLC, whilefulfilling high reliability, high data rate and low latencyrequirements. The orthogonal frequency-division multiplexing (OFDM)technology as agreed in 3rd Generation Partnership Project (3GPP) mayserve as a baseline for NR waveform. The scalable OFDM numerology, suchas the adaptive sub-carrier spacing, the channel bandwidth, and thecyclic prefix (CP), may also be used. Additionally, two coding schemesare considered for NR: (1) low-density parity-check (LDPC) code and (2)polar code. The coding scheme adaption may be configured based on thechannel conditions and/or the service applications.

Moreover, it is also considered that in a transmission time interval ofa single NR frame, a DL transmission data, a guard period, and an ULtransmission data should at least be included, where the respectiveportions of the DL transmission data, the guard period, the ULtransmission data should also be configurable, for example, based on thenetwork dynamics of NR. In addition, sidelink resource may also beprovided in an NR frame to support ProSe services orVehicle-to-Everything (V2X) services or NR sidelink services.

The term “and/or” herein is only an association relationship fordescribing associated objects, and represents that three relationshipsmay exist, for example, A and/or B may represent that: A exists alone, Aand B exist at the same time, and B exists alone. In addition, thecharacter “/” used herein generally represents that the former andlatter associated objects are in an “or” relationship.

In the NR protocols, the 2-step Random Access (RA) procedure may beconsidered to be used to facilitate the access of stand-alone NR-Uscenario. In addition, for the NR-U operation, a gNB may need assistanceinformation (e.g., NR-U measurement result, such as the Received SignalStrength Indication (RSSI) measurement/Reference Signal Received Power(RSRP) measurement/Reference Signal Received Quality (RSRQ)measurement/Signal to Interference plus Noise Ratio (SINR) measurementand the Channel Occupancy (CO) measurement of at least one unlicensedfrequency carrier) to configure the appropriate NR-U radio resource(s)based on a given Received Signal Strength Indication(RSSI)-threshold/RSRP-threshold/RSRQ-threshold/SINR-threshold (e.g.,being provided within the measurement configuration or Early measurementconfiguration). One of the reasons is that a hidden node that is nearbythe UE may interfere the NR-U packet receptions at the UE. The gNB mayneed the UE's measurement report (e.g., the RSSI/RSRP/RSRQ/SINR & COmeasurement observed by the UE) to determine the NR-U radio resourceassigned to the UE (since the serving RAN may not detect the hidden nodeby itself alone). Moreover, a fast reporting approach to theRSRP/RSRQ/RSSI/SINR & CO measurement report of the NR-U standaloneSpCell(s) may be critical to maintain the air link quality when theSpCell is operating as an NR-U standalone cell. In addition, a UE mayneed to provide an NR-U measurement report (continuously/aperiodically)to reflect the varying channel quality. Therefore, a fast and efficient(from the perspective of PHY resource or time consumption) measurementreporting mechanism may be necessary for operations on licensed orunlicensed bands. In addition, it may be also beneficial for the RAN todynamically configure an NR-U carrier to adapt the fast-changingunlicensed bands. Besides, NR-U carrier, the same solution may alsoapplicable to RAN/UEs operating on licensed bands.

FIG. 1 is a diagram illustrating a UE configured with several CCs withmultiple active BWPs in each CC, in accordance with an implementation ofthe present disclosure. Each CC or BWP may be operating on the licensedor unlicensed bands. For example, a CC or BWP operating on theunlicensed bands may be referred to as an NR-U CC or NR-U BWP; a CC orBWP operating on the licensed bands may be referred to as an NR CC or NRBWP.

Referring to FIG. 1, the UE 102 may be configured with one or more thanone serving cells (e.g., NR-U cells or NR cells operating on licensedbands) by the serving RAN 104. Each serving cell is operating on oneoperating component carrier (e.g., among the CC#1˜CC#K). For eachserving cell, the UE 102 may be further configured with one or more thanone active Bandwidth Part (BWP). Thus, the serving RAN 104 may need theUE to provide the RSSI/RSRP/RSRQ/SINR measurement and/or the COmeasurement to the serving RAN in an efficient way. Additionally, theRAN 104 may include one or more than one BS (e.g., an NR gNB or an LTEeNB). Each BS may broadcast one or more than one cell Identity (ID),such as a Physical Cell ID (PCI) or cellidentiy in the PhysicalBroadcasting Channel (PBCH), which may be used to identify a unique cellin a Public Land Mobile Network (PLMN) or Non-Public Network (NPN). Asshown in FIG. 1, the cell(s) may be operating on the CC#1 to the CC #K,where K is a positive integer. The UE 102 may identify each cell bymonitoring the cell IDs delivered through the physical channels.

In some implementations, a UE may transmit a measurement report (e.g.,an NR-U measurement report) to the serving BS (e.g., the gNB or the eNB)through a 2-step RA procedure.

FIG. 2 illustrates a signaling flow of carrier management through a2-step RA procedure, in accordance with an implementation of the presentdisclosure.

As shown in FIG. 2, in action 206, the UE 202 may perform themeasurement negotiation with the serving RAN 204 (or serving cell). Insome implementations, the UE 202 may receive the measurementconfiguration by receiving the broadcasting system information or theUE-specific control signaling (e.g., RRCRelease message) from theserving RAN 204.

In action 208, the UE 202 may provide a first message (msgA), which mayinclude a preamble and a payload of the msgA, to the RAN 204. In someimplementations, the payload of the msgA may include at least one of thefollowing: 1) a measurement report (e.g., an (NR-U/NR) measurementreport), 2) an indication indicating that the measurement report isavailable, and 3) a UL Buffer Status Report (BSR). In someimplementations, the preamble part of the msgA may be transmitted on aPhysical Random Access Channel (PRACH) and the payload of the msgA maybe transmitted on a Physical Uplink Shared Channel (PUSCH).

In action 210, after receiving the msgA, the RAN 204 (e.g., the servingcell of the UE) may reply to the UE 202 with a second message (msgB). Insome implementations, the msgB may include at least one of thefollowing: 1) a Random Access Response (RAR) message and 2) a dedicatedcontrol signaling (e.g., the Radio Resource Control (RRC) signaling,such as the RRC setup message (RRCSetup or RRCConnectionSetup), the RRCresume message (RRCResume or RRCConnectionResume), the RRC releasemessage (RRCRelease or RRCConnectionRelease), the RRC re-establishmentmessage (RRCReestablishment or RRCConnectionReestablishment), or the RRCconnection reconfiguration message (RRCReconfiguration orRRCConnectionReconfiguration). It is noted that relative to broadcastsignaling, dedicated (control) signaling may refer to the signaling thatis sent by a BS to one or more specific objects (e.g., UE(s)). In someimplementations, the RAN 204 (or serving cell of the UE) mayre-configure the NR/NR-U radio resource (e.g., the information ofNR/NR-U cell activation/de-activation, the NR/NR-U BWP configuration,the UL configured grant configuration, the DL-SPS configuration) in thepayload of the msgB if the measurement report is provided in msgA. Insome implementations, a part of the msgB may be transmitted by theDownlink Control Information (DCI) in a Physical Downlink ControlChannel (PDCCH) and another part of the msgB may be transmitted in aPhysical Downlink Shared Channel (PDSCH), where the location of theResource Blocks (RBs) in the PDSCH may be configured by the DCI in themsgB. In some implementations, the msgB may be transmitted in a PDCCHonly (e.g., the DCI that includes the whole msgB may be transmitted inthe PDCCH).

In some implementations, the RAN 204 (or serving cell) may provide an ULgrant in the msgB. The UE 202 may also provide a measurement report(e.g., an measurement report) on the given UL grant. In someimplementations, there may be a report indicator provided in the msgB toindicate to the UE 202 to provide a measurement report. In someimplementations, the RAN 204 (or serving cell) may provide the UL grantby referring to an UL-BSR in the msgA.

In some implementations, a UE may deliver a part of the measurementreport (e.g., the RSSI and CO measurements on the SpCell, which may bemore critical to the serving RAN) in the msgA. The UE may also furtherindicate that the remaining part of the measurement report is availablein the msgA. After receiving the msgA, the serving RAN (or serving cell)may further provide a UL grant in the msgB for the UE to transmit theremaining part of the measurement report.

In some implementations, after receiving the msgA, the serving cell mayprovide the feedback information to a UE via the msgB. In someimplementations, various formats of the msgB may be applied to reply theUE. In some implementations, a serving cell may just provide anAcknowledgment (ACK)/Negative-Acknowledgment (NACK) message in the msgBas the feedback of the msgA reception. In some implementations, aserving RAN (e.g., a serving cell) may further re-configure the (NR-U)radio resource in the msgB to the UE (e.g., via the RRC signaling, suchas the RRCConnectionReconfiguration message). In some implementations, aserving cell may or may not configure a periodic Physical Uplink ControlChannel (PUCCH) radio resource for a Scheduling Request (SR) on the(NR-U) carrier(s) for requesting the UL grants to transmit the (NR-U)measurement report.

In some implementations, a UE may perform measurements when operating inan (NR/LTE) RRC inactive state or an (NR/LTE) RRC idle state. Suchmeasurements may be referred to as an “early measurement”. Moreover, theearly measurement configuration and corresponding measurement resultsmay still be stored while the UE moves from the (NR/LTE) RRC inactivestate to the (NR/LTE) RRC idle state. In addition, in some embodiments,the UE may keep implementing early measurement (and/or keep themeasurement results) based on the stored early measurement configuration(e.g., while the UE moves from the RRC inactive state to the RRC idlestate within the same RAT). In some additional embodiments, the UE maykeep implementing early measurement (and/or keep the measurement result)based on the stored early measurement configuration while the UE movesfrom the RRC inactive state to the RRC idle state of different RAT).

FIG. 3A illustrates a signaling flow of an early measurement procedure,in accordance with an implementation of the present disclosure. As shownin FIG. 3A, in action 306, the UE 302 may receive a measurementconfiguration (e.g., an early measurement configuration) from the RAN304 (e.g., a serving cell) via dedicated control signaling (e.g.,RRCRelease message), broadcasting system information (e.g., SystemInformation Block type 11, SIB 11), or on-demand system information. Forexample, the UE 302 may receive the measurement configuration via an RRCrelease message with Suspend configuration, so the UE may move to theRRC inactive state after receiving the RRC release message with Suspendconfiguration. Moreover, the measurement configuration may be providedindependently with the Suspend configuration in the RRCRelease message.Therefore, the UE may still keep the measurement configuration after theUE moves from RRC inactive state to RRC idle sate (in contrast, theSuspend configuration may be removed (or released) after the UE movesfrom RRC inactive state to RRC idle state). In contrast, in someembodiments, the measurement configuration may be provided within theSuspend configuration (So, it means the measurement configuration isvalid only while the UE is staying in RRC inactive state). In thiscondition, the UE may release the measurement configuration after the UEmoves from the RRC inactive sate to RRC idle state. Moreover, in someembodiments, the stored measurement result may or may not be removedwith the release of measurement configuration. In another example, theUE 302 may receive the measurement configuration via an RRC releasemessage without Suspend configuration, so the UE may move to the RRCidle state after receiving the RRC release message (without Suspendconfiguration). Then, the UE may start to implement measurement based onthe measurement configuration while the UE is staying in RRC idle state.

In action 308, when the UE 302 operates in the RRC inactive state or RRCidle state, the UE 302 may perform the early measurement based on thereceived (early) measurement configuration. The early measurement may beperformed by the UE 302 on the licensed bands or unlicensed bands. Forexample, if the early measurement is performed on the unlicensed bands(which may be referred to as “NR-U early measurement”), the earlymeasurement configuration may include parameter(s) for the UE 302 toapply the NR-U DL-Reference Signal Received Power (RSRP)/DL-ReferenceSignal Received Quality (RSRQ)/Signal to Interference plus Noise Ratio(SINR) measurement, and/or the RSSI and CO measurement on the NR-Ucarriers of the NR-U serving cells/BWPs (and neighbor cells in someimplementations). In some embodiments, if the early measurement areperformed on the unlicensed bands (which may be referred to as “NR earlymeasurement”), the early measurement configuration may includeparameter(s) for the UE 302 to implement the NR DL-Reference SignalReceived Power (RSRP)/DL-Reference Signal Received Quality (RSRQ)/Signalto Interference plus Noise Ratio (SINR) measurement, and/or the RSSI onthe NR carriers of the NR serving cells/BWPs (and neighbor cells in someimplementations).

In action 310, the UE 302, if operating in the RRC inactive state, maytransmit the msgA to the serving RAN 304. The msgA may include, forexample, an RRC resume request message with/without an indication thatthe “early measurement report (e.g., NR-U measurement and/or NRmeasurement) is available” while the RRC inactive UE 302 is requestingto resume its own RRC connection with the serving RAN 304.

After receiving the msgA successfully, the serving RAN 304 may providethe msgB to the UE 302. The msgB may include a dedicated RRC message(e.g., RRC resume message, RRC Setup message or RRC re-establishmentmessage) and the (NR-U) radio resource allocation (e.g., the (NR-U) ULradio resource allocation in the RAR message (e.g., in the SuccessRARmessage), or the radio resource configuration in theRRCConnectionReconfiguration message). In some implementations, the UEmay set one bit in the msgA to “1” to show that the early measurement isavailable. In some implementations, the UE may set one bit in the msgAto “1” to show that the early measurement is available and also requesta certain amount of UL radio resources (e.g., by sending a UL BSR in themsgA) to transmit the early measurement report to the serving RAN.

In action 312, after receiving the msgA, the serving RAN 304 (or servingcell) may transmit the msgB with the UL grant to the UE 302. In action314, after receiving the msgB successfully, the UE 302 may transmit ameasurement report (e.g., an NR-U measurement report and/or an NRmeasurement report) on the given UL grant. In some otherimplementations, the UE 302 may not set an indication in the msgA thatthe “early measurement is available,” but may transmit a UL-BSR in themsgA for UL data transmission. In some implementations, after receivingthe msgA, the serving RAN (or serving cell) may transmit the msgB withUL grant for the UE, and the UE may transmit an early measurement reportvia the received UL grant. In this condition, the serving RAN (orserving cell) may/may not indicate to the UE its request for the earlymeasurement in the msgB.

FIG. 3B illustrates a signaling flow of an early measurement procedurethrough a 4-step random access procedure, in accordance with animplementation of the present disclosure. As shown in FIG. 3B, in action336, the UE 332 may receive a measurement configuration (e.g., an earlymeasurement configuration) from the RAN 334 (e.g., a serving cell) viadedicated control signaling (e.g., RRCRelease message), broadcastingsystem information (e.g., System Information Block type 11, SIB11), oron-demand system information. For example, the UE 332 may receive themeasurement configuration via an RRC release message with Suspendconfiguration, so the UE may move to the RRC inactive state afterreceiving the RRC release message with Suspend configuration. In anotherexample, the UE 332 may receive the measurement configuration via an RRCrelease message without Suspend configuration, so the UE may move to theRRC idle state after receiving the RRC release message (with Suspendconfiguration).

In action 338, when the UE 332 operates in the RRC inactive state or RRCidle state, the UE 332 may perform the early measurement based on thereceived (early) measurement configuration. The early measurement may beperformed by the UE 332 on the licensed bands or unlicensed bands. Forexample, if the early measurement is performed on the unlicensed bands(which may be referred to as “NR-U early measurement”), the earlymeasurement configuration may include parameter(s) for the UE 332 toapply the NR-U DL-Reference Signal Received Power (RSRP)/DL-ReferenceSignal Received Quality (RSRQ)/Signal to Interference plus Noise Ratio(SINR) measurement, and/or the RSSI and CO measurement on the NR-Ucarriers of the NR-U serving cells/BWPs (and neighbor cells in someimplementations).

When the 4-step RA procedure is initiated on the UE side, the UE maytransmit a preamble (msg1) to the serving RAN, as shown in the msg1 inthe action 340. After receiving the msg1 successfully, the serving RAN334 may provide the Random Access Response message (msg2) to the UE 332in the action 342. The msg2 (e.g., a SuccessRAR message) may include aRandom Access-Radio Network Temporary Identifier (RA-RNTI) to indicatethat the msg1 is received successfully by the serving BS. In addition,(NR-U) UL radio resource allocation may also be included in the RARmessage for UE to transmit the following msg3 in the UL direction to theserving BS.

Then, in action 344, the UE 332, if operating in the RRC inactive state,may transmit the msg3 to the serving RAN 334. The msg3 may include, forexample, an RRC resume request message with/without an indication thatthe “early measurement report (e.g., NR-U measurement) is available”while the RRC inactive UE 332 is requesting to resume its own RRCconnection with the serving RAN 334. In some implementations, the UE mayset one bit in the msg3 to “1” to show that the early measurement (forNR-U) is available. In some implementations, the UE may set one bit inthe msg3 to “1” to show that the early measurement (for NR-U) isavailable and also request a certain amount of UL radio resources totransmit the early measurement report to the serving RAN. In someadditional implementations, UL BSR may also be included in the msg3 forUL radio resource request.

After receiving the msg3 successfully, the serving RAN 334 (or servingcell) may transmit the Network Response to UE 332 in action 346. To UE332, UE 332 may check whether the serving cell has received the msg3successfully by receiving the network response from the RAN 334. Then,UE 332 may try to decode the Network Response by using a UEidentification (e.g., a (temporary) C-RNTI, which may be configured bythe serving RAN in the Random Access Response message). UE 332 receivesthe Network Response message successfully after the UE 332 decoding theNetwork Response message by using the (temporary)C-RNTI successfully.The Network Response message may include a dedicated RRC message (e.g.,RRC resume message, RRC Setup message or RRC re-establishment message)and the (NR-U) UL radio resource allocation (e.g., the (NR-U) UL radioresource allocation for the UE to transmit the pending MeasurementReport.

In action 348, after receiving the Network Response message from theserving RAN 334 successfully, the UE 332 may transmit a measurementreport (e.g., an NR-U measurement report) on the given UL grant. In someother implementations, the UE 332 may not set an indication in the msg3to indicate that the “early measurement is available,” but may transmitan UL-BSR in the msg3 for UL data transmission. In some implementations,after receiving the msg3, the serving RAN (or serving cell) may transmitthe Network Response message (Msg4) with the UL grant for the UE, andthe UE may transmit an early measurement report via the received ULgrant. In this condition, the serving RAN (or serving cell) may indicateto the UE its request for the early measurement in the msg4 (e.g., inthe dedicated RRC message such as RRC resume message, RRC Setup messageor RRC re-establishment message).

In some implementations, the early measurement configuration may beprovided to the UEs via broadcasting message (e.g., system informationor on-demand system information in the NR protocols), not via the RRCrelease message. However, it is also worthy to note that, in thiscondition, the UE may also receive the UE-specific early measurementconfiguration in an RRC message (e.g., the RRC Release message or theRRC reconfiguration message) and the UE may still apply the UE-specificNR-U measurement configuration, rather than the cell-specific earlymeasurement configuration. Here, the UE-specific early measurementconfiguration may be associated with different radio access technologies(RATs), such as NR, E-UTRA, or NR-U, License Assisted Access (LAA).

In some implementations, the early measurement configuration mayindicate whether the UE is allowed to transmit the early measurementreport (to the serving cell) through the 2-step RA procedure (e.g., anRA procedure including the msgA transmission and the msgB reception). Insome implementations, there may be a 2-step RA procedure configurationprovided in the system information or in the RRC signaling to the UE toindicate whether the UE is allowed to transmit the early measurementreport through the 2-step RA procedure.

Although some implementations of the present disclosure are describedbased on the NR-U measurement, the present disclosure is not limitedthereto. For example, the proposed implementations may be alsoapplicable to NR/LTE protocols in the licensed bands. In addition, (partof) the implementations of the NR-U measurement (e.g., via the earlymeasurement configuration) may also be applicable to an RRC idle UE.

Implementations of (NR-U) Measurement

In some implementations, from the perspective of UE, the target NR-Ucarrier for the NR-U measurement and/or for the proposed 2-step RAprocedure may be an Spcell (e.g., the PCell in a Master Cell Group (MCG)of the UE, a PSCell in a Secondary Cell Group (SCG)), a Secondary Cell(SCell) (which may be in an activated state, a deactivated state, or adormant state), or a PUCCH (Physical Uplink Control Channel) SCell. APUCCH SCell may be a cell configured with the PUCCH physical resource.

The methods described herein may be based on the assumption that the UEoperates in the RRC connected state in some implementations. However,the methods may be also applicable to the UE(s) operating in RRCinactive/idle state (e.g., via the early measurement configuration) insome other implementations.

In some implementations, a UE may be configured with multiple candidatesof NR-U carriers (or NR-U BWPs). Thus, the UE may perform RSSImeasurement and/or CO measurements on these candidates continuously(e.g., based on the given NR-U measurement configuration). In addition,the UE may report the RSSI & CO measurement to the serving cell throughthe 2-step RA procedure. After receiving the msgA, the serving cell mayconfigure the NR-U radio resource on the monitored NR-U carrier. Themethods can be applied to help the UE report the appropriate NR-Ucarrier/BWP (and/or help the UE report the non-appropriate NR-Ucarrier/BWP). By taking the UE mobility into account, the UE may provideits measurement report on the msgA effectively and the handoverperformance in the NR-U may also be improved (e.g., the gNB may providethe handover command or the conditional handover command, such as theRRC connection reconfiguration message (RRCConnectionReconfiguration) inthe msgB).

Although, in some implementations, the methods are based on the NR-U COmeasurement and the RSSI report, the methods may also be applied toreport other measurement results (e.g., the NR-U RSRP/RSRQ/RSSI/SINRmeasurement report or NR RSRP/RSRQ/SINR/RSSI measurement report, thebeam measurement, or the measurement of other RATs, such as Wi-Fi).

Moreover, the methods may also be applicable to other RATs without beinglimited by the NR-U. For example, the methods may be applied to LAA inthe LTE protocols.

In NR-U, the 2-step RA procedure (e.g., for the NR-U measurement reporttransmitted through the 2-step RA procedure) may be implemented inparallel with other UL packet delivery procedures (e.g., the NR-Umeasurement report through the configured grants or the NR-U measurementtransmission via the SR/BSR request for the UL grant). A UE may initiatethe Listen-Before-Talk (LBT) procedures on a PRACH, a PUCCH, and on theconfigured grant (e.g., a PUSCH) respectively for an NR-U measurementreport while the UL carrier is implemented on the unlicensed band(s).The UE may transmit the NR-U measurement report based on the result ofthe parallel LBT procedures. In addition, the UE may trigger theseprocedures without regard to the order of these LBT events. The NR-Umeasurement report can be transmitted faster in time.

In some implementations, the NR-U UL carrier may be implemented on awideband carrier (e.g., a 100 Mega Hertz (MHz) continuous bandwidth inthe frequency domain) on an unlicensed band. In addition, the widebandcarrier may be divided into several separated and non-overlappedsub-channels (For example, the 100 MHz carrier may be separated into 5independent sub-channels, where each sub-channel may occupy 20 MHzbandwidth) in the frequency domain. In some implementations, eachsub-channel may be configured with an independent PRACH configurationand a PUSCH configuration. The UE may perform the LBT procedure on thewideband carrier or any combination of the sub-channels independently.For the msgA delivery, the UE may transmit a msgA on one of thesub-channels (e.g., on the corresponding PRACH (& PUSCH) resource) forwhich the LBT procedure is successful. So, to the UE, the LBT bandwidth,which is the range of the bandwidth that the UE performs the LBTprocedure, may lie on the bandwidth of one sub-channel. The UE mayreport the NR-U measurement report (especially the RSSI and CO) to theserving cell effectively. In some implementations, more than one msgAmay be transmitted independently by the UE on all or a subset of thesub-channels on which the corresponding LBT procedures are successfully.In this condition, the serving cell may reply one msgB (also on theassociated PDCCH/PDSCH associated with the sub-channel) to each msgArespectively in the corresponding sub-channel(s). In someimplementations, the UE may transmit one (or more than one) msgA only ifthe LBT procedure is successful at the UE in all the configured LBTbandwidths (in other words, the LBT is successful on the wide NR-Ucarrier).

1. Negotiation Procedure

FIG. 4 illustrates a signaling flow of a measurement negotiationprocedure, in accordance with an implementation of the presentdisclosure.

As shown in FIG. 4, in action 408, the RAN 404 (e.g., a gNB or a servingcell) may transmit a measurement configuration (e.g., an NR-Umeasurement configuration) to the UE 402 via the dedicated controlsignaling (e.g., via an RRC message, such as anRRCConnectionReconfiguration message).

In some implementations, the UE 402 may need to indicate to the RAN 404that the UE 402 can support the RSSI measurement and the CO measurementby sending a particular Information Element (IE)“rssi-AndChannelOccupancyReporting”={support} in the UL measurementcapability message to the RAN 404. As shown in action 406, the UE 402may transmit its UL measurement capability message to the RAN 404. Insome implementations, the UE 402 may indicate therssi-AndChannelOccupancyReporting to the RAN 404 only when the DL LAA orNR-U operation is supported by the UE capability. In someimplementations, the UE 402 may indicate to the RAN 404 that the UE 402is capable of performing the “NR-U measurement” (or NRmeasurement/E-UTRA measurement/LAA measurement) via the UL measurementcapability message. An example Text Proposal (TP) is shown below:

rssi-AndChannelOccupancyReporting={support} (otherwise, this IE may beabsent if the UE does not support RSSI & CO measurement report)

Indicates whether the UE supports performing measurements and reportingof RSSI and CO. This field may be included only if DL LAA or NR-Uoperation is supported in UE capability.

In some implementations, as a reply to the UL measurement capabilitymessage, the RAN 404 may configure a measurement configuration for theearly measurement to the UE through the dedicated control signaling(e.g., in an RRC message, such as an RRCRelease message or anRRCConnectionReconfiguration message). In some implementations, themeasurement configuration for the early measurement may be provided in asuspend configuration (Suspendconfig), which means the UE 402 may notreuse this measurement configuration after the UE 402 transitions fromthe RRC inactive state to the RRC idle state. In some otherimplementations, the measurement configuration for the early measurementmay be provided independently with the Suspendconfig in the RRCReleasemessage. In some implementations, the UE 402 may reuse this measurementconfiguration after transitioning from the RRC inactive state to the RRCidle state. In some implementations, an ongoing early measurementprocedure may not be interrupted by the RRC state transition.

In some implementations, after the UE 402 informs the RAN 404 of therssi-AndChannelOccupancyReporting={support} in the UL measurementcapability message, the IE rssi-AndChannelOccupancyReporting may stillbe regarded as “not support” automatically to the serving RAN 404 if theUE 402 further informs the serving RAN 404 that the UE 402 is under apower saving mode (or a temporarily capability restriction mode) whilethe UE 402 is in a specific condition (e.g., overheating condition). Theserving RAN 404 may not expect that the UE 402 may report the (NR-U)measurement report (e.g., the CO report) through the 2-step/4-step RAprocedure. The rssi-AndChannelOccupancyReporting may be regarded as‘support’ automatically to the serving RAN 404 again after the UE 402sends another dedicated control message to the serving RAN 404 toindicate that the UE 402 leaves the power saving mode (or temporarilycapability restriction mode). In some implementations, there may be anIE “rssi-AndChannelOccupancyReporting_2stepRA”={support} to indicatethat the UE supports the RSSI and CO report through the 2-step RAprocedure on the NR-U carriers (in comparison, this IE may not beprovided in the UE capability signaling (e.g., e.g., the UL measurementcapability message) if the UE does not support the NR-U measurementreporting through the 2-step RA procedure on the NR-U carriers). In someimplementations, there may be an IE “NRU_2StepRA”={support} in the UEcapability signaling to indicate that the UE 402 supports the 2-step RAprocedure in the NR-U frequency carriers. The serving RAN 404 may beinformed that the UE 402 supports the NR-U measurement reporting (e.g.,NR-U RSSI or Channel Occupancy Report) through the 2-step RA procedureafter receiving both the “NRU_2StepRA”={support} and the“rssi-AndChannelOccupancyReporting”={support} in UE capabilitysignaling. In contrast, the serving RAN 404 may expect that the UE 402does not support the NR-U measurement reporting through the 2-step RAprocedure if either the “NRU_2StepRA” or the“rssi-AndChannelOccupancyReporting” (or both) is (are) not shown in theUE capability signaling. In some other implementations, the serving RAN404 may be informed that the UE 402 supports the NR-U measurementreporting through the 2-step RA procedure after receiving the“NRU_2StepRA”={support} alone. That is, the NRU_2StepRA may implicitlyindicate that the NR-U measurement reporting through the 2-step RAprocedure is supported to the UE 402. Here, the UE capability report mayalso be associated with different RATs, such as NR (e.g.,NRU_2StepRA={support}), E-UTRA (e.g., EUTRA_2StepRA={support}), NR(e.g., NR_2StepRA={support}), or LAA (e.g., LAA_2StepRA={support}).

In some implementations, the serving RAN 404 may enable (or disable) theUE 402 to provide the (NR-U) measurement report by transmitting the(NR-U) measurement configuration to the UE 402. For example, the servingRAN 404 may set one bit in the (NR-U) measurement configuration to “1”(or “enabled”) to enable the UE 402 to provide the (NR-U) measurementreport via the 2-step RA procedure (and/or 4-step RA procedure). Incontrast, the serving RAN 404 may set one bit in the (NR-U) measurementconfiguration to “0” (or “disabled”) to disable the UE 402 fromproviding the (NR-U) measurement report through 2-step RA procedure(and/or 4-step RA procedure). In some implementations, theenable/disable bit may be provided in (on-demand) system information.

The serving RAN 404 may also enable (or disable) the UE 402 to providethe (NR/E-UTRA) measurement report by transmitting the (NR/E-UTRA)measurement configuration to the UE 402. For example, the serving RAN404 may set one bit in the (NR/E-UTRA) measurement configuration to “1”(or “enabled”) to enable the UE 402 to provide the (NR/E-UTRA)measurement report via the 2-step RA procedure (and/or 4-step RAprocedure). The serving RAN 404 may set one bit in the (NR/E-UTRA)measurement configuration to “0” (or “disabled”) to disable the UE 402from providing the (NR/E-UTRA) measurement report through 2-step RAprocedure (and/or 4-step RA procedure). In some implementations, theenable/disable bit may be provided in (on-demand) system information.

In some implementations, the UL measurement capability message (e.g.,the NR-U measurement capability message) may be transmitted via thededicated control signaling (e.g., UE Capability Information). In someimplementations, the UE may provide the UE Capability Information, whichincludes the (NR/NR-U/E-UTRA) measurement capability message, afterreceiving the UE capability enquiry message from the serving RAN 404.

One example of the (NR-U) measurement configuration is in Table 1:

TABLE 1 (NR-U) Measurement configuration measId In some implementations,the NR-U Measurement report may be associated with a measId (measurementidentity), which each measId is associated with one measurement objectand one report configuration. The measurement object and reportconfiguration are pre-configured in the dedicated control signaling(e.g., RRC Connection Re-configuration message). Measurement objectIndicates the target frequency, cell, and some control parameters for UEto Configuration perform NR-U measurement. One implementation of theNR-U Measurement object is provided in Table 2. Report configurationIndicates the triggering conditions, NR-U measurement report procedure,or configuration for the proposed NR-U measurement report through2-step/4- step RA procedure. One implementation of the Reportconfiguration is provided in Table 3.

The measurement object (MO) configuration may include the targetfrequency and cell information (and/or BWP information) for the UE tolocate the target frequency/cell. In some implementations, additionalIEs TimeToTrigger and TimeToTrigger-SF may also be provided in themeasurement object configuration. An example of the measurement objectconfiguration is shown in Table 2.

TABLE 2 Measurement Object configuration Carrier Frequency Indicates thetarget frequency carrier (e.g., by ARFCN (absolute radio-frequencychannel number) for NR CC (ARFCN-ValueNR) or for E-UTRA(ARFCN-ValueEUTRA), E-ARFCN) Cell identity Indicates the Cell identityof the configured cell for this MO. In some implementations, the Cellidentity is represented by the physical cell identity (PCI) orcellidentity of the configured Cell. In some other implementations, theCell identity is represented by the SCellindex (pre- configured to theUE through dedicated control signaling) of the configured cell. In someimplementations, the Cell identity is represented by theservingCellIndex of the configured cell. Bandwitdh Part (BWP) In someimplementations, serving cell may configure the BWP identity to thecorresponding identity measurement object. In this condition, the UE isalready configured with at least one Bandwidth Part configuration in thecorresponding cell. One BWP configuration may include: (a) BandwidthPart identity (b) Frequency domain location and bandwidth of thisbandwidth part. (c) Cyclic prefix (d) Subcarrier space (e) RACH resourceconfiguration, (f) Reference signaling configuration (e.g., channelstate information reference signal (CSI- RS), or Synchronization SignalBlock (SSB)). So, the UE may be informed how to perform NR-U measurement& report on the indicated BWP based on the received BWP ID. rmtc-ConfigParameters applicable to RSSI and CO measurement on the carrierfrequency indicated by carrierFreq or by the BWP identity. rmtc-PeriodIndicates the RSSI measurement timing configuration (RMTC) periodicityfor this frequency. Value ms40 corresponds to 40 ms periodicity, ms80corresponds to 80 ms periodicity and so on. In some implementations,rmtc-Period =ENUMERATED {ms40, ms80, ms160, ms320, ms640},rmtc-SubframeOffset Indicates the RSSI measurement timing configuration(RMTC) subframe offset for this frequency. The value ofrmtc-SubframeOffset should be smaller than the value of rmtc-Period. Forinter-frequency measurements, this field is optional (e.g.,rmtc-SubframeOffset = INTEGER(0..639)) and if it is not configured, theUE chooses a random value as rmtc- SubframeOffset for measDuration whichshall be selected to be between 0 and the configured rmtc-Period withequal probability. measDuration Number of consecutive symbols for whichthe Physical Layer reports samples of RSSI (Received Signal StrengthIndication). The value may be {sym1, sym14, sym28, sym42, sym70}, wheresym1 corresponds to one symbol, sym14 corresponds to 14 symbols, and soon. TimeToTrigger Specifies the time period during which one specifictriggering criteria must be met as long as the TimeToTrigger in order totrigger a NR-U measurement report. timeToTrigger-SF Indicates thescaling factor for TimeToTrigger adjustment based on the UE's speedstate while doing NR-U measurements. In this IE, different scalingfactors for the UE in different speed states (e.g., Low-mobility,medium-mobility, high-mobility) may be configured to the UE.measCycleSCell The parameter is used only when an SCell is configured onthe frequency indicated by the measObject and is in deactivated state orthe SCell is not configured. Value range of measCycleSCell may be{sf160, sf256, sf320, sf512, sf640, sf1024, sf1280, spare1}, whereinsf160 corresponds to 160 sub-frames, sf256 corresponds to 256 sub-framesand so on.

Additionally, the report configuration may be provided in the (NR-U)measurement configuration to configure the UE when and how to performthe NR-U measurement reporting to the serving RAN. An example of thereport configuration is shown in Table 3.

TABLE 3 Report Configuration MeasID MeasId is used to identify ameasurement configuration, i.e., linking of a measurement object and areporting configuration. The UE may identify when to report themeasurement results through the (2-step/4-step) RA procedure. TriggeringEvents ‘Periodical’ ReportInterval may also be included in the ReportConfiguration if ‘periodical’ event is configured. The value ofReportInterval may be {ms120, ms240, ms480, ms640, ms1024, ms2048,ms5120, ms10240, min1, min6, min12, min30, min60, spare3, spare2,spare1}, which Value ms120 corresponds with 120 ms, ms240 correspondswith 240 ms and so on, while value min1 corresponds with 1 min, min6corresponds with 6 min and so on. ‘Event O1’: The CO (of the configuredNR-U carrier) is above a threshold (T_(o1)). T_(o1) may also be includedin the Report Configuration if Event O1 is configured. The value ofT_(o1) may be an integer in the range between (0, 100). ‘Event O2’: TheCO (of the configured NR-U carrier) is under a threshold ((T_(o2))).T_(o2) may also be included in the Report Configuration if Event O2 isconfigured. The value of T_(o2) may be an integer in the range between(0, 100). channelOccupancyThreshold RSSI threshold which is used for COevaluation. 2-StepRACHReport gNB may further enable/disable the UE toreport the CO measurement through 2- step RA procedure after the UEindicates that the UE itself is capable of rssi-AndChannelOccupancyReporting. 2-StepRACHReport={enabled, disabled} Alsonote: (1) In some implementations, the default setting of the NR-Ureporting through 2- step RA procedure is ‘enabled’. The gNB may furtherprovide this IE to disable the procedure by setting therssi-AndChannelOccupancyReporting=disabled. Otherwise, the gNB need notfurther indicate this IE. (2) In some implementations, the defaultsetting of the NR-U reporting through 2- step RA procedure is‘disabled’. Tthe gNB may further provide this IE to enable the procedureby setting the rssi-AndChannelOccupancyReporting = enabled. Otherwise,the gNB need not further indicate this IE. (3) In some implementations,there is no default setting of NR-U measurement reporting through 2-stepRA procedure and the gNB must provide this IE in every configuration (orre-configuration). (4) In some implementations, the 2stepRACHReport maybe enabled/disabled based on the mobility state of the UE.2-StepRACHReport = Sequence {Low-mobility, medium-mobility, high-mobility} So, gNB may further indicate that the 2-StepRACHReport isenabled while the UE is under low, medium mobility, or high mobility byconfiguring 2-StepRACHReport = {Low-mobility, medium-mobility,high-mobility} After receiving the configuration above, the UE may notimplement 2- StepRACHReport while the UE is at high-mobility state. Insome implementations, the UE may apply 4-stepRACHReport if the 2-StepRACHReport is not allowed (or not configured) by the serving cell.In some implementations, UE may determine its mobility state based onthe rules in LTE specifications. Note: in some implementations, this IEmay be absent. The UE may obtain whether the serving cell enable/disable2-stepRACHReport by checking the IE ‘2-StepRACHReport configuration’ isprovided. 2-StepRACHReport configuration Configuration for the UE toprovide NR-U measurement report through the 2-step RA procedure (If the2-stepRACHReport is enabled to the UE). In another implementation, thisIE may be provided but the UE is not allowed to apply this IE because2-stepRACHReport=disabled). This configuration may further comprise: (1)One or more than one preamble for the UE to transmit in the msgA. (2)Physical resource block configuration in time domain, frequency domain,code domain, for the UE to transmit msgA. (3) Maximum number of 2-stepRA attempts for the NR-U measurement report. The UE may abandon NR-Umeasurement report through the 2-step RA procedure (such that the UE maytransmit the NR-U measurement report by requesting uplink grant on PUSCH(Physical Uplink Shared Channel)) if the number of 2-step RA attemptfailure is over the maximum number of attempts. (4) RA-search spaceconfiguration for the UE to monitor the msgB. In some implementations,gNB may also provide a ‘default’ 2-Step RA configuration throughbroadcasting (e.g., (on demand) system information) or dedicated controlsignalling. If 2-stepRACHReport configuration is absent, the UE mayapply the NR- U measurement report based on the default configuration of2-Step RA procedure. In some implementations, the default 2-stepRAconfiguration may be overwritten by the 2-stepRACHReport configurationtransmitted through dedicated control signalings. In addition, for ahandover improvement scenario, the UE may be pre-configured withdedicated 2-step RA resource, which includes a dedicated preamble (bypre- configuring a preambleindex to the UE), a dedicated physicalresource (by pre- configuring a physical resource block index)

2. msgA Signaling

In some implementations, after receiving the (NR-U) measurementconfiguration successfully, a UE may start to monitor the (NR-U)carriers and then report the (NR-U) measurement report through the2-step RA procedure. The msgA may include a preamble and a payload(e.g., the control signaling delivered through a PUSCH). In someimplementations, the control signaling to an RRC connected UE mayinclude the UE ID (e.g., the Cell-Radio Network Temporary Identifier(C-RNTI)) and the (NR-U) measurement report (e.g., the RSSI & COmeasurement report). In some implementations, the preamble may beselected by the UE autonomously from a set of applicable preamblesconfigured by the serving cell (e.g., configured by the (NR-U)measurement configuration or configured by the system information (e.g.,SystemInformationBlockType1) broadcasted by the serving cell). In someimplementations, the preamble(s) and the associated RA resource may beconfigured in the (NR-U) measurement configuration for the UE to applythe (contention-based/contention-free) 2-step RA procedure.

In some implementations, the (NR-U) measurement report may include theUE's measurement result implemented by following the (NR-U) measurementconfiguration. In some implementations, in the msgA, the preamble andthe following payload (e.g., payload msgA, transmitted via the PUSCH)may be transmitted independently. For example, the preamble and thepayload msgA may be transmitted in different physical radio resourceblock(s) and the UE may need to apply the LBT protocol to the preambletransmission and the payload msgA delivery independently. There may bean association between the physical resource blocks for the preamble andpayload msgA transmission and the UE(s) may only need to apply the LBTprotocols one time to transmit both the preamble and the payload msgA.

Examples of the (NR-U) measurement report in the msgA are summarized inTable 4.

TABLE 4 Format Description Size requirement 1. (Indication Event 1) TheCO measurement result of There may be up to 23 + X bits for RSSI and COof under/ one NR-U cell/BWP (the NR-U cell may or report: above givenmay not be the same as the NR-U (1) 7 bits for RSSI report (by referringto TS threshold). carrier/BWP which the msgA is transmitted) 36.331,RSSI result may be presented by RSSI- is lower/higher than a giventhreshold. Range (integer(0...76)). ⇒ (A) The NR-U measurement report(2) 1 bit in the NR-U measurement report (CO includes one bit, whereinthe bit is set measurement is above/below the given to 1 if themeasurement result on the threshold). cell/BWP/sub-channel is higherthan (3) Up to 7 bits for cell/BWP indication. the threshold. The bitmay be set to 0 if 5 bits cell index to represent the indicated cell.the measurement result on the (For example, PCI, SCellindex orServCellIndex concerned cell/BWP/sub-channel is (integer(0...31)) lowerthan the given threshold 2 bits BWP index (channelOccupancyThreshold).(4) 8 bits Medium Access Control (MAC) ⇒ (B) The threshold may beconfigured subheader. by dedicated control signaling (e.g., (5) X bitsRRC signaling overhead for RRC Connection Reconfiguration MeasurementReport. message or RRCRelease message) or Signaling overhead (24 bits):through broadcasting message (e.g., (6) 16 bits UE ID (e.g.,C-RNTI-value) System information or on-demand (7) 8 bits MAC subheader.System information in New Radio ⇒ About 47 + X bits in the msgA.protocols). (assuming 72 bits msgA size). ⇒ (C) In some implementations,UE There may be up to 29 +X bits for RSSI and CO obtains CO measurementby setting the report: rounded percentage of sample values (1) 7 bitsfor RSSI report (by referring to TS which are beyond the 36.331, RSSIresult may be presented by RSSI- channelOccupancyThreshold within allRange (integer(0...76)). the sample values in the report Interval. (2) 7bits in the NR-U measurement report 2. (Percentage (Event 2) COmeasurement report of a (percentage). report) NR-U cell (The NR-Ucell/BWP may or (3) Up to 7 bits for cell/BWP/sub-channel may not be thesame as the NR-U indication. carrier/BWP/sub-channel which the msgA 5bits cell index to represent the indicated cell. is transmitted) islower/higher than a given (For example, SCellindex or ServCellIndexthreshold. (integer(0...31)) ⇒ UE obtains CO measurement by setting 2bits BWP index. the rounded percentage of sample (4) 8 bits MACsubheader. values which are beyond the (5) X bits RRC signaling overheadfor channelOccupancyThreshold within all Measurement Report. the samplevalues in the report Interval. Signaling overhead (24 bits): ⇒ In msgA,the value of CO may be (1) 16 bits UE ID (e.g., C-RNTI-value)represented by an integer between (2) 8 bits MAC subheader. (0, 100),wherein Value 0 corresponds ⇒ About 53 + X bits in the msgA (assuming to0, value 1 to 0.01 (1%), value 2 72 bits msgA size). corresponds to 0.02(2%), and so on. (1) The value X depends on the RRC signaling structurefor the measurement report (at least 3 bits for RRC signaling typeindication & up to 8 bits MeasID indication). (2) In some otherimplementations, the UE may just indicate the (NR-U) measurement report(or Early measurement) is available (1 bit signaling overhead). (3) Insome implementations, the RSSI and CO measurement report may be providedin the MAC Control Element (CE). FIGS. 5 and 6 are diagrams illustratingdifferent formats of MAC CEs, in accordance with implementations of thepresent disclosure. As shown in FIG. 5, an RSSI report 502 with a 1-bitindication 504 for the CO may be provided in a MAC CE. Also, referringto FIG. 6, a 7-bit RSSI report 602 and a 7-bit CO report 604 (inpercentage) with a 1-bit reserved field 606 are provided in a MAC CE. Insome implementations, the MAC sub-header, in which the Logical ChannelID (LCID) may be defined to indicate the RSSI/CO report, may also betransmitted along with the MAC CE. After decoding the MAC sub-headersuccessfully, the serving cell may be informed how to decode theinformation contained in the MAC CE. (4) The msgA may further includecontrol messages, such as short BSR (Buffer Status Report) or shorttruncated BSR (16 bits) or (UL) Power Headroom Report (24 bits) for ULpacket delivery (e.g., NR-U measurement report). (5) The UE may transmitthe whole NR-U Measurement report (not being limited byRSSI&ChannelOccupancy report) by providing UL-BSR in the msgA forMeasurement report.

In some implementations, a UE may provide the RSSI & CO measurement ofthe target NR-U carrier (e.g., associated with an PCI, SCell index(Scellindex) of a measurement ID (measID)) in the msgA. In someimplementations, since the msgA size may be limited to less than 56 or72 bits, the UE may not transmit the precise RSSI & CO measurementreport in the msgA. Thus, the UE may transmit a simplified indicationfor the (NR-U) measurement report. For example, the UE may transmit asimplified under-Threshold indicator in the msgA to inform the servingcell that the CO measurement in the corresponding NR-U carrier observedby the UE is below a pre-defined threshold (e.g., the T_(o2) in theEvent O2 in Table 3). In some implementations, the UE may also transmitanother simplified Above-Threshold indicator in the msgA to inform theserving cell that the CO measurement in the corresponding NR-U carrierobserved by the UE is above a pre-defined threshold (e.g., the T₀₁ inthe Event O1 in Table 3). In some implementations, the UE may transmit aUL BSR in the msgA (e.g., for the NR-U measurement report (for an RRCconnected UE) or the early measurement report (for an RRC idle/inactiveUE)). After receiving the msgA, the serving cell may configure the ULresource grant (by referring to the received UL-BSR) in the msgB for theUE to report the (NR-U) measurement report (or the early measurementreport). In the present disclosure, an “RRC connected UE” may refer to aUE operating in an RRC connected state, an “RRC inactive UE” may referto a UE operating in an RRC inactive state, and an “RRC idle UE” mayrefer to a UE operating in an RRC idle state.

In some implementations, to an RRC inactive UE, the serving cell mayprovide the UL grant for the early measurement report only when thesecurity is activated by the serving cell in the msgB (e.g., the UEsends the RRCResumeRequest message via the msgA and the serving cellresponds to the UE with the RRCResume message in the msgB with the ULgrant. In some implementations, the security may be activated at the UEside after the UE receives the RRCResume message successfully. Inaddition, the UE may provide the early measurement report with theactivated security keys. In some other implementations, the serving cellmay directly request the UE to report the (NR-U) measurement report inthe msgB (e.g., by indicating the early measurement request andconfiguring the UL grant in the msgB with the RRCResume message),without regard to whether the UE indicates the early measurement isavailable or whether the UE provides the UL-BSR in the msgA. The UE maytransmit the early measurement to the serving cell in the followingRRCResumeComplete message, which may be transmitted in Signaling RadioBearer 1 (SRB1) with activated security keys.

In some other implementations, to an RRC idle UE, the serving cell mayprovide the UL grant for the early measurement report only when thesecurity is activated by the serving cell in the msgB (e.g., the UEsends the RRCSetupRequest (or RRCConnectionRequest) message via the msgAand the serving cell responds to the UE with the RRCSetup (orRRCConnectionSetup) message in the msgB with the UL grant. In someimplementations, the security may be activated at the UE side after theUE receives the RRCSetup (or RRCConnectionSetup) message successfully.In addition, the UE may provide the early measurement report with theactivated security keys. In some other implementations, the serving cellmay directly request the UE to report the (NR-U) measurement report inthe msgB (e.g., by indicating the early measurement request andconfiguring the UL grant in the msgB with the RRCSetup (orRRCConnectionSetup) message), without regard to whether the UE indicatesthe early measurement is available or whether the UE provides the UL-BSRin the msgA. The UE may transmit the early measurement to the servingcell in the following RRCSetupComplete (or RRCConnectionSetupComplete)message, which may be transmitted in Signaling Radio Bearer 1 (SRB1)with activated security keys. In some other embodiments, the UE mayindicate that early measurement is available (e.g., early measurementassociated with NR, NR-U, E-UTRA or LAA available) in theRRCSetupComplete (or RRCConnectionSetupComplete) message by triggeringone additional indicator (with the associated RAT) in theRRCSetupComplete (or RRCConnectionSetupComplete) message as ‘1’ (or‘true’). Then, the serving cell may request the early measurement reportfrom the UE by sending a ‘Early measurement Enquiry message (with atleast one of the indicated associated RAT)’ to the UE. After receivingthe ‘Early measurement Enquiry message’, the UE would deliver therequested early measurement report (e.g., retained by the UE before theRRC Connection Establishment procedure) to the serving cell in onededicated Uplink (RRC) signaling after the UE RRC ConnectionEstablishment procedure is finished.

In some implementations of the 4-step RA procedure, the serving cell mayprovide the UL grant to an RRC inactive UE for the early measurementreport only when the security is activated by the serving cell in theNetwork Response message (msg4) (e.g., the UE sends the RRCResumeRequestmessage via the msg3 and the serving cell responds to the UE with theRRCResume message in the msg4 with the UL grant. In someimplementations, the security may be activated at the UE side after theUE receives the RRCResume message successfully. In addition, the UE mayprovide the early measurement report with the activated security keys.In some other implementations, the serving cell may directly request theUE to report the (NR-U) measurement report in the msg4 (e.g., byindicating the early measurement request and configuring the UL grant inthe msg4 with the RRCResume message), without regard to whether the UEindicates the early measurement is available or whether the UE providesthe UL-BSR in the msg3. The UE may transmit the early measurement to theserving cell in the following RRCResumeComplete message, which may betransmitted in Signaling Radio Bearer 1 (SRB1) with activated securitykeys.

In some implementations of 4-step RA procedure, to an RRC idle UE, theserving cell may provide the UL grant for the early measurement reportonly when the security is activated by the serving cell in the NetworkResponse message (msg4) (e.g., the UE sends the RRCSetupRequest (orRRCConnectionRequest) message via the msg3 and the serving cell repliesthe UE with the RRCSetup (or RRCConnectionSetup) message in the msg4with the UL grant. In some implementations, the security may beactivated at the UE side after the UE receives the RRC(Connection)Setupmessage successfully. In addition, the UE may provide the earlymeasurement report with the activated security keys. In some otherimplementations, the serving cell may directly request the UE to reportthe (NR-U) measurement report in the msg4 (e.g., by indicating the earlymeasurement request and configuring the UL grant in the msg4 with theRRC(Connection)Setup message), without regard to whether the UEindicates the early measurement is available or whether the UE providesthe UL-BSR in the msg3. The UE may transmit the early measurement to theserving cell in the following RRC(Connection)SetupComplete message,which may be transmitted in Signaling Radio Bearer 1 (SRB1) withactivated security keys.

In some additional embodiments, the serving cell may transmit theRRCSetup message to the UE after receiving the RRCResumeRe quest messagefrom the UE. The serving cell may still directly request the UE toreport the (NR-U) measurement report in the msgB (e.g., by indicatingthe early measurement request and configuring the UL grant in the msgBwith the RRCSetup message), without regard to whether the UE indicatesthe early measurement is available or whether the UE provides the UL-BSRin the msgA. The UE may transmit the early measurement to the servingcell in the following RRCSetupComplete message, which may be transmittedin Signaling Radio Bearer 1 (SRB1) with activated security keys. Thisembodiment may utilize the 2-step RA procedure or 4-step RA procedure.

3. msgA Delivery

In some implementations, after determining the format of the msgA, theUE may send the msgA on the configured RACH resource. The RACH resourcemay also be configured in the (NR-U) measurement configuration to the UEor in the system information (e.g., the SystemInformationBlockType1)broadcast by the serving cell. In some implementations, the RACHresource for the 2-step RA procedure may be configured on a UE basis, ona measurement configuration (associated with the measID) basis, on areport configuration basis, or on a measurement object basis.

FIG. 7 is a diagram illustrating a procedure of msgA transmissionaccording to the beam operation, in accordance with an implementation ofthe present disclosure. As shown in FIG. 7, the PRACH#1 702, the PRACH#2704, the PRACH#3 706 and the PRACH#4 708 may appear periodically in thetime domain and each PRACH may be configured on one corresponding beamdirection to the gNB. For example, the PRACH#1 702 may correspond to thebeam direction 772, the PRACH#2 704 may correspond to the beam direction774, the PRACH#3 706 may correspond to the beam direction 776, and thePRACH#4 708 may correspond to the beam direction 778.

In some implementations, the UE may select one PRACH (e.g., among thePRACH#1 702, the PRACH#2 704, the PRACH#3 706 and the PRACH#4 708) totransmit the msgA 710 based on the DL/UL beam correspondence and theDownlink-Synchronization Signal Block (DL-SSB) monitoring condition. Insome other implementations, the UE may transmit the msgA 710 on morethan one configured PRACH (e.g., the msgA 710 may transmitted on thePRACHs #1˜#4 702708) if the DL/UL correspondence does not exist. In someimplementations, the UE may transmit more than one msgA 710 in onePRACH. In some implementations, the independent PRACH (resources)associated with each beam direction (which may be regarded as aTransmission Configuration Indicator (TCI)-state) may be furtherconfigured in each sub-channel. The UE may determine the PRACH resourcebased on the selected sub-channel for the msgA transmission.

4. Configuration of Cross-Cell Report and Target Cell Indication

In some implementations, the UE may only be configured with severalcells for the early measurement report through the 2-step RA procedure(or 4-step RA procedure). Moreover, there may be an association betweenthe measured (NR-U) cell and the serving cell of the 2-step RA procedure(such that the message format in the msgA, such as a cell index, may befurther optimized to fulfill the msgA size limitation).

FIG. 8 is a diagram illustrating a cross-cell reporting procedureperformed by a UE, in accordance with the present disclosure. The UE mayindicate the (NR-U) measurement of one or more than one specific carrier(e.g., an NR-U carrier) via a cross-cell report. As shown in FIG. 8, theUE may utilize the measurement configuration from the serving cell toperform an NR-U measurement (e.g., based on the received NR-Umeasurement configuration) on the NR-U CC#1 802. In the NR-U measurementconfiguration, the serving cell may further indicate the associated cellfor the NR-U measurement report via the 2-step RA procedure (or 4-stepRA procedure).

Also referring to Table 5, the serving cell may configure one or morethan one target Component Carrier (CC) (e.g., NR-U CC#1 and NR-U CC#3)to be associated with the serving cell (e.g., by delivering the targetCC list in system information or RRCRelease message for the earlymeasurement configuration). Moreover, for each target component carrier,the UE may further indicate the Subcarrier Spacing (e.g., 15 KHz, 30KHz, 60 KHz, 120 KHz) associated with the target CC in the earlymeasurement configuration. After receiving the target cell list, the UEmay apply early measurement on these configured target CCs based on theindicated subcarrier spacing. In some additional implementations, forone provided target CC, the serving cell may further indicate one ormore than one target cell for the early measurement (e.g., theassociated serving cell may also deliver the Physical Cell Identity(PCI) of these associated target cell(s) in the system information orRRCRelease message for the early measurement configuration). Afterreceiving the target cell list, the UE may informed that the target celllist would be applicable to the early measurement report (so, the UE maymeasure and store the DL measurement results of these indicated targetcells). The CC of the serving cell may also be included implicitly asone of the target CCs in the early measurement. One target cell listassociated with the CC which is also the operating component carrier ofthe serving cell may also be provided by the serving cell (e.g., throughbroadcasting system information or RRCRelease message). The UE maymeasure and the store the DL-measurement results associated with theprovided target cell list (and the serving cell). For early measurementreport, the UE may also initiate the 2-step RA procedure (or 4-step RAprocedure) with one selected cell, which may be the original servingcell or one selected cell from the received target cells, for the earlymeasurement report. However, it is also worthy to note, to one targetcomponent carrier, the UE may not be limited to measure only the cellsprovided in the target cell list associated with the target componentcarrier. Moreover, the UE may not be limited to only transmit earlymeasurement report to the cells provided in the target cell listassociated with the target component carrier. In some implementations,the serving cell, which provides the measurement configuration to the UE(e.g., through the RRCRelease message or through the broadcasting systeminformation), may also be implicitly included as one of the target cellfor measurement. Moreover, in some implementations, the servingfrequency carrier, which is the operating frequency carrier of theserving cell, may also be implicitly included as one of the targetcomponent carrier for measurement.

In some implementations, the PRACH resource of each associated cell maybe provided in the (NR-U) measurement report configuration. In someimplementations, the 2-step RA procedure may only be allowed on theSpCell (e.g., a PCell or a PSCell). For example, as shown in FIG. 8, theNR-U CC#2 804 may be the SpCell to the UE. However, it may also possiblethat the loading of serving SpCell(s) may be high and the serving cellmay configure the PRACH resource on the SCell(s) for the UE to providethe NR-U measurement report.

TABLE 5 (NR-U) measurement configuration for cross-cell Report TargetCell ID Associated Cell for cross-cell report Target CC (e.g., PCI)(e.g,. the serving cell) Note NR-U CC #1 T_CID #1 NR-U CID #3 1) One ormore than one NR-U CC #3 T_CID #2 NR-U CID #3 target cell may be linkedwith the same associated cell. 2) One or more than one target CC mayalso be linked with the same associated cell.

In some implementations, because a UE may report the (NR-U) measurementresults on the associated cell, the UE may need to further indicate thetarget cell ID (e.g., the T_CID#1 or the T_CID#2 shown in Table 5) ofthe corresponding (NR-U) measurement report. However, the size of theT_CID may be smaller than the maximum number of the aggregated cellsindicated in the 3GPP Technical Specification (e.g., TS 38.331 v15.0.0).For example, the maximum number of the aggregated cells may be 32 butthe size of the T_CID may be 3 bits if less than 8 NR-U cells areassociated with the UE. Thus, the size of the msgA may be smaller. Insome of the applications, the serving cell may operate on (NR/E-UTRA)licensed bands or (NR/E-UTRA) unlicensed bands and then the targetcomponent carriers may locate on (NR/E-UTRA) licensed bands or(NR/E-UTRA) unlicensed bands. In some additional applications, theserving cell may be an E-UTRAN cell and the target component carriersmay locate on NR licensed/un-licensed bands (so, the associated targetcells may be NR cells or NR-U cells). In some other applications, theserving cell may be an NR cell and the target component carriers maylocate on LTE licensed/un-licensed bands (so, the associated targetcells may be E-UTRAN cells or LAA cells).

5. SCell/BWP Management

In some implementations, the methods may be further extended to theSCells of different states. As shown in Table 6, there are severalstates (e.g., the activated (cell) state, the deactivated (cell) state,and the (cell) dormant state) of a configured SCell. In someimplementations, the UE may still apply the measurement without beingimpacted by the state transitions between each two of the (cell) states(or between each two of a subset of the indicated (cell) states) basedon the measurement configuration from the serving cell. The serving cellmay have more flexibility to consider the scheduling via the activatedcell(s), the deactivated cell(s), and the dormant cell(s) of a UE.Moreover, in some implementations, the UE may transmit the correspondingmeasurement report via the 2-step RA procedure (or the 4-step RAprocedure) on an activated cell, a deactivated cell, or a dormant cell.

TABLE 6 SCell State UE behavior Proposals Activated UE need to monitorPDCCH and (1) In this disclosure, gNB measurements. may configure a UEto perform (NR-U) Deactivated UE may not do neither PDCCH monitoringmeasurement on Activated cell, nor measurements Deactivated cell, orDormant Cell as the Dormant An intermediate state between SCellreference of serving cell scheduling on activation and deactivation,where UE skips NR-U carriers. PDCCH monitoring on the SCell and does (2)Moreover, the 2-step/4-step RA not expect to be scheduled on the SCell.It procedure (for NR-U measurement report may still perform measurementson the is also applicable to an activated cell, a SCell so thattransition to activation state Deactivated cell, or a dormant cell). canbe very quick.

In some implementations, each BWP in one (NR-U) cell may be configuredin the activated state/the deactivated state/the dormant state to oneUE. In some implementations, the proposed (NR-U) measurementconfiguration/report (e.g., implemented through the 2-step or 4-step RAprocedure) may be also applicable to BWPs of different sub-states (e.g.,including the activated state, the deactivated state and the dormantstate).

6. msgB Signaling

FIG. 9 illustrates a signaling flow between a UE and a PCell, inaccordance with an implementation of the present disclosure. As shown inFIG. 9, in action 908, the UE 902 may perform the measurement (e.g., theNR-U measurement and/or NR measurement). In action 910, the UE 902 maytransmit the msgA to the PCell (UL) 904′ on the licensed band withoutimplementing the LBT protocol. In action 912, after receiving the msgAfrom the UE 902, the serving cell (e.g., the PCell (DL) 904) may replythe msgB to the UE 902 based on the 2-step RA procedure in the NR-Uunlicensed band. For example, the PCell (DL) 904 may perform the LBTprocedure for the msgB delivery). In some implementations, the PCell(DL) 904 and the PCell (UL) 904′ may be paired in the Frequency DivisionDuplex (FDD) scenario. For example, a standalone NR cell is in theunlicensed band in the DL direction while the UL operation is operatedin the licensed band. The UE 902 may transmit the msgA on the PCell (UL)904′ without implementing the LBT protocols. The serving cell (e.g., thePCell (DL) 904) may need to apply the LBT protocols for the msgBtransmission. In some implementations, the UL grant in the msgB also maybe located on the licensed band. In action 912, the UE 902 may transmitthe measurement report to the PCell (UL) 904′ without LBT. Examples ofthe msgB design are provided in Table 7.

TABLE 7 Contents MSG B Format General In some implementations, the msgBmay comprise: Description (1) Random Access Response message (RARmessage); and (2) Dedicated (control) message (e.g., Radio ResourceControl Message or MAC Control Element) (payload_msgB, which may betransmitted on PDSCH). A. Random Access Response message the servingcell may provide the following messages in response to the msgA: (1)SuccessRAR message: ACK message to indicate to the UE that the servingcell has received the msgA (which contains the NR-U measurement or Earlymeasurement indication) successfully. (2) Fallback message: NACK messageto indicate to the UE that the serving cell does not receive the msgA(which contains the NR-U measurement or Early measurement indication)successfully. The serving cell may request the UE to fallback to the4-step RA procedure to re-transmit the msgA. (3) Backoff indication: Theserving cell may request the UE to re-transmit msgA after a certain timespan. The time span may be indicated by the serving cell in the backoffindication. In some other conditions, the time span may be chosen by theUE autonomously within a pre-defined range. In some implementations, (a)one explicit IE ‘RAR Type’ may be configured in msgB. The RAR Type mayinclude {SuccessRAR, FallbackRAR, BackoffRAR}. (b) The RAR type may beconfigured in the PDCCH (e.g., Downlink Control Information, DCI) to theUE or the PDSCH (e.g., MAC subheader (e.g., indicated by the logicalchannel ID in the MAC sub-header) or in the MAC SubPDU (e.g., onespecific ‘RAR Type’ in the MAC subPDU)). In some other implementations,there may be no explicit RAR Type IE in msgB. The UE may identify msgBtype implicitly by identifying the format of msgB. B. Dedicated(control) message In some implementations, the serving cell may replywith RRC signaling based on the msgA. For example, a. RRCSetup message(New Radio protocols) may be provided in the msgB (e.g. if the UEtransmits RRCSetupRequest message in msgA). b. RRCResume message may beprovided in msgB (e.g., if the UE transmits RRCResumeRequest message inmsgA). c. RRCRelease message may be provided in msgB (e.g., for theserving cell to re-direct an RRC Inactive UE to other targetfrequency(s) or Cell(s)). d. RRCConnectionRe-establishment message maybe provided (e.g. for the serving cell to instruct an RRC Inactive UE tore-establish RRC Connection) e. RRCReconfiguration message (e.g., forthe serving cell to configure radio resource, such as: DL-SPS(semi-persistent scheduling) configuration, UL configured grantconfiguration/activation/de-activation, DL/UL (first) bandwidth partconfigurations, SCell add/removal, on radio resource control onunlicensed bands/licensed bands. In one implementation, the serving cellmay provide the re-configuration based on the indicated NR-U measurementreport (and/or NR measurement report) in msgA (if there is any). Someconfigurations may also be provided in the msgB. For example, to an RRCConnected UE, the msgB may further include the following messages: 1.NR-U SCell activation/de-activation message through the MAC ControlElement attached in the msgB. 2. NR-U configured uplink grantactivation/de-activation message through the DCI in the msgB reception.(in this condition, the UE may need to reply with configured uplinkgrant confirmation in one MAC CE transmitted to the serving cell) 3.Duplication activation/de-activation message through the MAC ControlElement attached in the msgB. In some implementations, the RRC messagesto the corresponding UE may be multiplexed in the common control channel(CCCH). In some implementations, the RRC messages may be multiplexed ina dedicated control channel. UE identifier: Note: UE ID is also includedin the msgB for UE to decode msgB successfully. The UE ID may beincluded in the following ways: (1) RA-RNTI (e.g., the UE may decode RARmessage by applying RA-RNTI, which is associated with the selectedpreamble and PRACH occasion in msgA). (2) C-RNTI (e.g., the UE maydecode the dedicated (control) signaling by applying C-RNTI in thecorresponding Cell group wherein the RA procedure is triggered). (3)Temporary C-RNTI (e.g., the UE may decode the dedicated (control)signaling by applying temporary C-RNTI in the corresponding Cell groupwherein the RA procedure is triggered). . RAR message SuccessRARSuccessRAR may include (any combination of) the following informationElements: a. Contention resolution ID b. (Temporary) C-RNTI c. TAcommand d. UL grant (e.g., for Early measurement report or UL datatransmission). The UL grant may be absent in the SuccessRAR message. e.In some implementations, Early measurement request indication (e.g., 1bit) may be indicated explicitly in the SuccessRAR. After receiving theindication, the UE may transmit the Early measurement report to theserving cell on the received UL grant. There may be no explicitindicator for the Early measurement enquiry. The UE may be informed thatit must provide the Early measurement report automatically afterobtaining the UL grant in the SuccessRAR message. FallbackRAR Theserving cell may trigger the fallback mechanism to let the UE tore-transmit the msgA. FallbackRAR may include (any combination of) thefollowing information Elements. a. RAPID b. UL grant (to retransmit themsgA payload, which contains the NR-U measurement report in thisdisclosure). c. TC-RNTI (Temporary C-RNTI) or C-RNTI. d. TA commandBackoff (1) The serving cell may provide a Backoff indicator in the RARmessage (e.g., BI field in the indication MAC subPDU). (2) Afterreceiving the Backoff indicator, the UE may set a backoff parameter(e.g., PREAMBLE BACKOFF) to value of the BI field of the MAC subPDU. (3)The UE may select a random backoff time according to a uniformdistribution between 0 and the PREAMBLE BACKOFF.

FIG. 10 illustrates a flowchart of a procedure 1000 performed by a UE,in accordance with an implementation of the present disclosure. Althoughactions 1002, 1004 and 1006 are delineated as separate actionsrepresented as independent blocks in FIG. 10, these separatelydelineated actions should not be construed as necessarily orderdependent. The order in which the actions are performed in FIG. 10 isnot intended to be construed as a limitation, and any number of thedescribed blocks may be combined in any order to implement the procedure1000, or an alternate method. Moreover, one or more of the actions 1002,1004 and 1006 may be omitted in some of the present implementations.

In action 1002, a UE may receive a first measurement configuration(e.g., in the system information) from a first serving cell. The firstmeasurement configuration may indicate at least one first cellapplicable for being measured by the UE in a first RRC state (e.g., anRRC idle state or an RRC inactive state). The first cell(s) may beconsidered as the cell(s) applicable for being measured by the UE duringthe early measurement. For example, during the early measurement, the UEmay determine which cell to measure based on the first measurementconfiguration, and measure the metric of the signal quality of theindicated first cell(s) (if it can be detected) to obtain thecorresponding measurement result. In some implementations, the firstcell(s) may include the first serving cell and/or other cell(s)configured in the first measurement configuration.

In some implementations, the first measurement configuration may furtherindicate a first carrier frequency to which the at least one first cellbelongs. In some implementations, the first measurement configurationmay further indicate one or more than one second carrier frequency forthe early measurement. In some implementations, one or more cell IDs(e.g., PCI(s)) of the target cell(s) associated with the first carrierfrequency or second carrier frequency for measurement may also beincluded in the first measurement configuration. In someimplementations, the first measurement configuration may furtherindicate a subcarrier spacing associated with the at least one firstcell operating on the first carrier frequency.

In action 1004, the UE may perform, in the first RRC state (e.g., in anRRC idle state or an RRC inactive state), a first measurement operation(e.g., early measurement) based on the first measurement configurationto generate a first measurement result of the at least one first cell.

In action 1006, the UE may retain the first measurement result when theUE transitions from the first RRC state to a second RRC state. Forexample, once the UE obtains the first measurement result in the firstRRC state, the UE may not drop/cancel/release the first measurementresult when the UE transitions from the first RRC state to the secondRRC state (e.g., an RRC idle state, an RRC inactive state, or an RRCconnected state, which is different from the first RRC state). In otherwords, the UE may perform the RRC transition (e.g., switching from thefirst RRC state to the second RRC state) withoutdropping/canceling/releasing the first measurement result, so after theRRC transition, the UE may still keep the first measurement result. Insome implementations, the first RRC state may be associated with a firstRadio Access Technology (RAT) and the second RRC state may be associatedwith a second RAT. The first RAT and the second RAT may be the same asor different from each other. For example, one of the first RAT and thesecond RAT may be NR, and the other of the first RAT and the second RATmay be LTE.

FIG. 11 illustrates a signaling flow among a UE and multiple servingcells, in accordance with an implementation of the present disclosure.

As shown in FIG. 11, in action 1108, a UE 1102 may receive a firstmeasurement configuration from a first serving cell 1104 (e.g., via RRCsignaling). The first measurement configuration may indicate at leastone first cell applicable for being measured by the UE in a first RRCstate (e.g., an RRC idle state or an RRC inactive state) and optionallya first carrier frequency to which the at least one first cell belongs.

In action 1110, the UE 1102 may receive a second measurementconfiguration in the system information from the first serving cell 1104(e.g., via RRC signaling). The second measurement configuration mayindicate at least one second cell applicable for being measured by theUE in the first RRC state and optionally a second carrier frequency towhich the at least one second cell belongs. The second cell(s) may beconsidered as the cell(s) applicable for being measured by the UE duringthe early measurement.

In some implementations, the at least one first cell may be associatedwith a first RAT and the at least one second cell may be associated witha second RAT. For example, the first cell may be associated with the NR(or LTE) and the second cell may be associated with LTE (or NR).

In some implementations, in action 1112, the UE 1102 may furtherperform, in the first RRC state (e.g., an RRC idle state or an RRCinactive state), a second measurement operation (e.g., the earlymeasurement) based on the second measurement configuration to generate asecond measurement result of the at least one second cell.

In some implementations, compared to the first measurement resultobtained based on the first measurement configuration, the firstmeasurement result may be associated with the first RAT and the secondmeasurement result may be associated with the second RAT. For example,the first measurement result may be associated with the NR (orLTE/E-UTRA) and the second measurement result may be associated with LTE(or NR).

In action 1114, the UE 1102 may transmit a measurement report includingthe first measurement result and/or second measurement result. The UE1102 may transmit the measurement report to the first serving cell 1104only, the second serving cell 1106 only, or both the first serving cell1104 and the second serving cell 1106. In some implementations, thefirst serving cell 1104 may be associated with the first RAT (e.g., NRor E-UTRA) and the second serving cell may be associated with the secondRAT (e.g., E-UTRA or NR).

FIG. 12 illustrates a signaling flow among a UE and multiple servingcells, in accordance with an implementation of the present disclosure.

As shown in FIG. 12, in action 1208, a UE 1202 may receive a firstmeasurement configuration from a first serving cell 1204 (e.g., via RRCsignaling). The first measurement configuration may indicate at leastone first cell applicable for being measured by the UE in a first RRCstate (e.g., an RRC idle state or an RRC inactive state) and optionallya first carrier frequency to which the at least one first cell belongs.

In action 1210, the UE 1202 may receive a measurement report requestfrom a second serving cell 1206. In some implementations, the firstserving cell 1204 may be associated with a first RAT and the secondserving cell 1206 may be associated with a second RAT. For example, thefirst serving cell 1204 may be associated with NR (or LTE) and thesecond serving cell 1206 may be associated with LTE (or NR). In someimplementations, the measurement report request may be furtherassociated with a third RAT, which may be either NR or E-UTRA. In someimplementations, the third RAT may be different from the first RAT orsecond RAT. In addition, different RAT parameters may be configured inthe early measurement configuration for measurement and report, whereeach RAT parameter may be specific to (or directed to) a particular typeof RAT (e.g., NR or E-UTRA or NR-U). The UE may determine whether andhow to apply an early measurement configuration to a particular RATbased on whether the early measurement configuration is configured withone (or more than one) RAT parameter directed to the particular RAT.

In some implementations, the measurement report request may be includedin an RRC resume message. The UE 1202 may receive the RRC resume messagein an RAR message during a 2-step RA procedure or a 4-step RA procedure.In a 2-step RA procedure, the messages may be identified as msgA (e.g.,an RA preamble and a payload) and msgB (e.g., an RAR); in a 4-step RAprocedure, the messages may be identified as msg1 (e.g., an RApreamble), msg2 (e.g., an RAR message), msg3 (e.g., a Radio ResourceControl (RRC) connection/resume request) and msg4 (e.g., an RRCcontention setup/RRC connection Resume message or contention resolutionmessage). The RRC resume message including the measurement reportrequest may be included in the msgB of the 2-step RA procedure orincluded in the msg4 of the 4-step RA procedure.

In some other implementations, the measurement report request may beincluded in an RRC setup message. The UE 1202 may receive the RRC setupmessage in an RAR message during a 2-step RA procedure or a msg4 in a4-step RA procedure. For example, the RRC setup message including themeasurement report request may be included in the msgB of the 2-step RAprocedure or included in the msg4 of the 4-step RA procedure.

In action 1212, the UE 1202 may perform the (early) measurement in theRRC inactive state or the RRC idle state and generate a firstmeasurement result accordingly.

In action 1214, the UE 1202 may transmit, in response to receiving themeasurement report request, the first measurement result to the secondserving cell 1206.

In some implementations, the first measurement result may be included inan RRC resume complete message if the corresponding measurement reportrequest is transmitted via an RRC resume message. In some otherimplementations, the first measurement result may be included in an RRCsetup complete message if the corresponding measurement report requestis transmitted via an RRC setup message.

According to various implementations of the present disclosure, a UE maytransmit the NR-U measurement report (or request a UL grant for the NR-Umeasurement report) via the 2-step RA procedure. A serving cell mayprovide control signaling or indication in the msgB (which is theresponse to the msgA transmitted by the UE) in the 2-step RA procedure.In addition, the serving cell may configure and request an earlymeasurement report on the 2-step RA for the NR-U measurement reporting.The method(s)/procedure(s) described herein are not limited by NR-U andit may also be applicable to other scenarios.

FIG. 13 illustrates a block diagram of a node 1300 for wirelesscommunication, in accordance with various aspects of the presentdisclosure. As shown in FIG. 13, a node 1300 may include a transceiver1306, a processor 1308, a memory 1302, one or more presentationcomponents 1304, and at least one antenna 1310. The node 1300 may alsoinclude an RF spectrum band module, a BS communications module, anetwork communications module, and a system communications managementmodule, Input/Output (I/O) ports, I/O components, and power supply (notexplicitly shown in FIG. 13). Each of these components may be incommunication with each other, directly or indirectly, over one or morebuses 1324. In one implementation, the node 1300 may be a UE or a BSthat performs various functions described herein, for example, withreference to FIGS. 1 through 12.

The transceiver 1306 having a transmitter 1316 (e.g.,transmitting/transmission circuitry) and a receiver 1318 (e.g.,receiving/reception circuitry) may be configured to transmit and/orreceive time and/or frequency resource partitioning information. In someimplementations, the transceiver 1306 may be configured to transmit indifferent types of subframes and slots including, but not limited to,usable, non-usable and flexibly usable subframes and slot formats. Thetransceiver 1306 may be configured to receive data and control channels.

The node 1300 may include a variety of computer-readable media.Computer-readable media can be any available media that can be accessedby the node 1300 and include both volatile (and non-volatile) media andremovable (and non-removable) media. By way of example, and notlimitation, computer-readable media may include computer storage mediaand communication media. Computer storage media may include bothvolatile (and non-volatile) and removable (and non-removable) mediaimplemented according to any method or technology for storage ofinformation such as computer-readable.

Computer storage media includes RAM, ROM, EEPROM, flash memory (or othermemory technology), CD-ROM, Digital Versatile Disks (DVD) (or otheroptical disk storage), magnetic cassettes, magnetic tape, magnetic diskstorage (or other magnetic storage devices), etc. Computer storage mediadoes not include a propagated data signal. Communication media maytypically embody computer-readable instructions, data structures,program modules or other data in a modulated data signal such as acarrier wave or other transport mechanism and include any informationdelivery media. The term “modulated data signal” may mean a signal thathas one or more of its characteristics set or changed in such a manneras to encode information in the signal. By way of example, and notlimitation, communication media may include wired media such as a wirednetwork or direct-wired connection, and wireless media such as acoustic,Radio Frequency (RF), infrared and other wireless media. Combinations ofany of the above should also be included within the scope ofcomputer-readable media.

The memory 1302 may include computer-storage media in the form ofvolatile and/or non-volatile memory. The memory 1302 may be removable,non-removable, or a combination thereof. For example, the memory 1302may include solid-state memory, hard drives, optical-disc drives, etc.As illustrated in FIG. 13, the memory 1302 may store computer-readableand/or -executable instructions 1314 (e.g., software codes) that areconfigured to, when executed, cause the processor 1308 to performvarious functions described herein, for example, with reference to FIGS.1 through 12. Alternatively, the instructions 1314 may not be directlyexecutable by the processor 1308 but may be configured to cause the node1300 (e.g., when compiled and executed) to perform various functionsdescribed herein.

The processor 1308 (e.g., having processing circuitry) may include anintelligent hardware device, a Central Processing Unit (CPU), amicrocontroller, an ASIC, etc. The processor 1308 may include memory.The processor 1308 may process the data 1312 and the instructions 1314received from the memory 1302, and information received through thetransceiver 1306, the base band communications module, and/or thenetwork communications module. The processor 1308 may also processinformation to be sent to the transceiver 1306 for transmission throughthe antenna 1310, to the network communications module for transmissionto a core network.

One or more presentation components 1304 may present data indications toa person or other device. Examples of presentation components 1304 mayinclude a display device, speaker, printing component, vibratingcomponent, etc.

From the present disclosure, it is manifested that various techniquesmay be used for implementing the concepts described in the presentapplication without departing from the scope of those concepts.Moreover, while the concepts have been described with specific referenceto certain implementations, a person of ordinary skill in the art mayrecognize that changes may be made in form and detail without departingfrom the scope of those concepts. As such, the described implementationsare to be considered in all respects as illustrative and notrestrictive. It should also be understood that the present applicationis not limited to the particular implementations described above, butmany rearrangements, modifications, and substitutions are possiblewithout departing from the scope of the present disclosure.

What is claimed is:
 1. A method for handling measurement operations in awireless communication system performed by a User Equipment (UE), themethod comprising: receiving a first measurement configuration in systeminformation from a first serving cell, the first measurementconfiguration indicating at least one first cell applicable for beingmeasured by the UE in a first Radio Resource Control (RRC) state whichis an RRC idle state or an RRC inactive state; performing, in the firstRRC state, a first measurement operation based on the first measurementconfiguration to generate a first measurement result of the at least onefirst cell; and retaining the first measurement result when the UEtransitions from the first RRC state to a second RRC state.
 2. Themethod of claim 1, wherein the first measurement configuration furtherindicates a first carrier frequency to which the at least one first cellbelongs.
 3. The method of claim 2, wherein the first measurementconfiguration further indicates a subcarrier spacing associated with thefirst carrier frequency.
 4. The method of claim 2, further comprising:receiving a second measurement configuration in the system informationfrom the first serving cell, the second measurement configurationindicating at least one second cell applicable for being measured by theUE in the first RRC state and a second carrier frequency to which the atleast one second cell belongs.
 5. The method of claim 4, wherein the atleast one first cell is associated with a first Radio Access Technology(RAT) and the at least one second cell is associated with a second RAT.6. The method of claim 4, further comprising: performing, in the firstRRC state, a second measurement operation based on the secondmeasurement configuration to generate a second measurement result of theat least one second cell, the first measurement result being associatedwith a first RAT and the second measurement result being associated witha second RAT.
 7. The method of claim 1, further comprising: receiving ameasurement report request in an RRC resume message from a secondserving cell; and transmitting, in response to receiving the measurementreport request, the first measurement result to the second serving cellin an RRC resume complete message.
 8. The method of claim 7, wherein thefirst serving cell is associated with a first RAT and the second servingcell is associated with a second RAT.
 9. The method of claim 7, furthercomprising: receiving the RRC resume message in a Random Access Response(RAR) message during a 2-step Random Access (RA) procedure.
 10. Themethod of claim 7, further comprising: receiving the RRC resume messageduring a 4-step Random Access (RA) procedure.
 11. The method of claim 1,further comprising: receiving a measurement report request in an RRCsetup message from a second serving cell; and transmitting, in responseto receiving the measurement report request, the first measurementresult to the second serving cell in an RRC setup complete message. 12.The method of claim 11, wherein the first serving cell is associatedwith a first RAT and the second serving cell is associated with a secondRAT.
 13. The method of claim 11, further comprising: receiving the RRCsetup message in an RAR message during a 2-step Random Access (RA)procedure.
 14. The method of claim 11, further comprising: receiving theRRC setup message during a 4-step RA procedure.
 15. The method of claim1, wherein the first RRC state is associated with a first RAT and thesecond RRC state is associated with a second RAT.
 16. A User Equipment(UE) for handling measurement operations in a wireless communicationsystem, the UE comprising: a memory; and at least one processor coupledto the memory, the at least one processor being configured to: receive afirst measurement configuration in system information from a firstserving cell, the first measurement configuration indicating at leastone first cell applicable for being measured by the UE in a first RadioResource Control (RRC) state which is an RRC idle state or an RRCinactive state; perform, in the first RRC state, a first measurementoperation based on the first measurement configuration to generate afirst measurement result of the at least one first cell; and retain thefirst measurement result when the UE transitions from the first RRCstate to a second RRC state.
 17. The UE of claim 16, wherein the firstmeasurement configuration further indicates a first carrier frequency towhich the at least one first cell belongs.
 18. The UE of claim 17,wherein the first measurement configuration further indicates asubcarrier spacing associated with the first carrier frequency.
 19. TheUE of claim 17, wherein the at least one processor is further configuredto: receive a second measurement configuration in the system informationfrom the first serving cell, the second measurement configurationindicating at least one second cell applicable for being measured by theUE in the first RRC state and a second carrier frequency to which the atleast one second cell belongs.
 20. The UE of claim 19, wherein the atleast one first cell is associated with a first Radio Access Technology(RAT) and the at least one second cell is associated with a second RAT.21. The UE of claim 19, wherein the at least one processor is furtherconfigured to: perform, in the first RRC state, a second measurementoperation based on the second measurement configuration to generate asecond measurement result of the at least one second cell, the firstmeasurement result being associated with a first RAT and the secondmeasurement result being associated with a second RAT.
 22. The UE ofclaim 16, wherein the at least one processor is further configured to:receive a measurement report request in an RRC resume message from asecond serving cell; and transmit, in response to receiving themeasurement report request, the first measurement result to the secondserving cell in an RRC resume complete message.
 23. The UE of claim 22,wherein the first serving cell is associated with a first RAT and thesecond serving cell is associated with a second RAT.
 24. The UE of claim22, wherein the at least one processor is further configured to: receivethe RRC resume message in a Random Access Response (RAR) message duringa 2-step Random Access (RA) procedure.
 25. The UE of claim 22, whereinthe at least one processor is further configured to: receive the RRCresume message during a 4-step Random Access (RA) procedure.
 26. The UEof claim 16, wherein the at least one processor is further configuredto: receive a measurement report request in an RRC setup message from asecond serving cell; and transmit, in response to receiving themeasurement report request, the first measurement result to the secondserving cell in an RRC setup complete message.
 27. The UE of claim 26,wherein the first serving cell is associated with a first RAT and thesecond serving cell is associated with a second RAT.
 28. The method ofclaim 26, wherein the at least one processor is further configured to:receive the RRC setup message in an RAR message during a 2-step RAprocedure.
 29. The UE of claim 26, wherein the at least one processor isfurther configured to: receive the RRC setup message during a 4-step RAprocedure.
 30. The UE of claim 16, wherein the first RRC state isassociated with a first RAT and the second RRC state is associated witha second RAT.